You are just making s*it up. Meme is something you publicly posted it is not your personal info, you possibly agreed to transfer copyright to the site, if you still own it, of course you have right to delete it.

As for personal info, most meme websites don't require any accounts to create them, because it only makes the site less usable, but if the site do have accounts, you do have right to see/update your account, you have right to delete your account and be sure that if your account is deleted the data is actually gone.

> Meme is something you publicly posted it is not your personal info,

Very generous assumption on your part. Article 9 specifically says that anything revealing personal info like ethnicity, political affiliation, etc. is covered by GDPR. If I look at a Adam's list of authored memes and there's a bunch of pro-Democrat memes and I look at Bob's and it's all pro-Republican memes, then it's very easy to see a court ruling that a memes reveal political affiliation.